Talks and Events

The HI Environments of Galaxies: Clues to Galaxy Formation

Eric Wilcots (Wisconsin)

The combination of wide-field HI imaging and sensitive single-pointing
observations with the Very Large Array and and the Australia Telescope
Compact Array over the past few years has uncovered a wealth of
neutral gas lurking in the immediate environments of a number of
galaxies. Sorting through the various detections of gas around
galaxies, one finds that it tends to come in three flavors: very extended
and smooth; very extended, but either morphologically or
kinematically (or both!) chaotic; and discrete clumps of gas, some of
which seem to be devoid of stars.

The role of this far-flung HI in the evolution of the host galaxy
remains uncertain, but studies of HI around galaxies are excellent
probes of the processes by which galaxies formed in the first place and
provide critical tests of popular galaxy formation models. I will
present a review of what we know about HI around galaxies in a number
of different environments and what those studies are telling us about
how galaxies form.